I just have a question, thanks for the pagerank reply. The question is. Why do some pages in the internet have high PR with internal backlinks an example is http://en.wikipedia.org/ I am a bit confused. So I can have internal links to increase my PR without external links Am I right?
Actually Wikipedia has hundreds of thousands of external backlinks. That's why their pages have such high pageranks. Internal links can be used to redistribute pagerank within the site.
As mentioned above Wikipedia is a huge website and have a lot of thousands of links pointing to alot of inner pages with anchor text and high pagerank and in a lot of cases the linking website are theme related.
pagerank refers to ranking per page, not site as a whole internal linking sometimes referred to sites in the same IP, external quality links will surely help